From 79b45350131057250236e162ce7b3c0b291dc0a4 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Sat, 28 Apr 2018 22:28:16 -0700 Subject: tools/bpf: add a test for bpf_get_stack with tracepoint prog The test_stacktrace_map and test_stacktrace_build_id are enhanced to call bpf_get_stack in the helper to get the stack trace as well. The stack traces from bpf_get_stack and bpf_get_stackid are compared to ensure that for the same stack as represented as the same hash, their ip addresses or build id's must be the same. Acked-by: Alexei Starovoitov Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/test_progs.c | 70 +++++++++++++++++++++++++++++--- 1 file changed, 64 insertions(+), 6 deletions(-) (limited to 'tools/testing/selftests/bpf/test_progs.c') diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index 0ddbf34..aa336f0 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -906,11 +906,47 @@ static int compare_map_keys(int map1_fd, int map2_fd) return 0; } +static int compare_stack_ips(int smap_fd, int amap_fd, int stack_trace_len) +{ + __u32 key, next_key, *cur_key_p, *next_key_p; + char *val_buf1, *val_buf2; + int i, err = 0; + + val_buf1 = malloc(stack_trace_len); + val_buf2 = malloc(stack_trace_len); + cur_key_p = NULL; + next_key_p = &key; + while (bpf_map_get_next_key(smap_fd, cur_key_p, next_key_p) == 0) { + err = bpf_map_lookup_elem(smap_fd, next_key_p, val_buf1); + if (err) + goto out; + err = bpf_map_lookup_elem(amap_fd, next_key_p, val_buf2); + if (err) + goto out; + for (i = 0; i < stack_trace_len; i++) { + if (val_buf1[i] != val_buf2[i]) { + err = -1; + goto out; + } + } + key = *next_key_p; + cur_key_p = &key; + next_key_p = &next_key; + } + if (errno != ENOENT) + err = -1; + +out: + free(val_buf1); + free(val_buf2); + return err; +} + static void test_stacktrace_map() { - int control_map_fd, stackid_hmap_fd, stackmap_fd; + int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd; const char *file = "./test_stacktrace_map.o"; - int bytes, efd, err, pmu_fd, prog_fd; + int bytes, efd, err, pmu_fd, prog_fd, stack_trace_len; struct perf_event_attr attr = {}; __u32 key, val, duration = 0; struct bpf_object *obj; @@ -966,6 +1002,10 @@ static void test_stacktrace_map() if (stackmap_fd < 0) goto disable_pmu; + stack_amap_fd = bpf_find_map(__func__, obj, "stack_amap"); + if (stack_amap_fd < 0) + goto disable_pmu; + /* give some time for bpf program run */ sleep(1); @@ -987,6 +1027,12 @@ static void test_stacktrace_map() "err %d errno %d\n", err, errno)) goto disable_pmu_noerr; + stack_trace_len = PERF_MAX_STACK_DEPTH * sizeof(__u64); + err = compare_stack_ips(stackmap_fd, stack_amap_fd, stack_trace_len); + if (CHECK(err, "compare_stack_ips stackmap vs. stack_amap", + "err %d errno %d\n", err, errno)) + goto disable_pmu_noerr; + goto disable_pmu_noerr; disable_pmu: error_cnt++; @@ -1080,9 +1126,9 @@ err: static void test_stacktrace_build_id(void) { - int control_map_fd, stackid_hmap_fd, stackmap_fd; + int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd; const char *file = "./test_stacktrace_build_id.o"; - int bytes, efd, err, pmu_fd, prog_fd; + int bytes, efd, err, pmu_fd, prog_fd, stack_trace_len; struct perf_event_attr attr = {}; __u32 key, previous_key, val, duration = 0; struct bpf_object *obj; @@ -1147,6 +1193,11 @@ static void test_stacktrace_build_id(void) err, errno)) goto disable_pmu; + stack_amap_fd = bpf_find_map(__func__, obj, "stack_amap"); + if (CHECK(stack_amap_fd < 0, "bpf_find_map stack_amap", + "err %d errno %d\n", err, errno)) + goto disable_pmu; + assert(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null") == 0); assert(system("./urandom_read if=/dev/urandom of=/dev/zero count=4 2> /dev/null") == 0); @@ -1198,8 +1249,15 @@ static void test_stacktrace_build_id(void) previous_key = key; } while (bpf_map_get_next_key(stackmap_fd, &previous_key, &key) == 0); - CHECK(build_id_matches < 1, "build id match", - "Didn't find expected build ID from the map"); + if (CHECK(build_id_matches < 1, "build id match", + "Didn't find expected build ID from the map")) + goto disable_pmu; + + stack_trace_len = PERF_MAX_STACK_DEPTH + * sizeof(struct bpf_stack_build_id); + err = compare_stack_ips(stackmap_fd, stack_amap_fd, stack_trace_len); + CHECK(err, "compare_stack_ips stackmap vs. stack_amap", + "err %d errno %d\n", err, errno); disable_pmu: ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE); -- cgit v1.1